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B1681




Anti-Theft

Pinpoint Test G: DTC B1681

Refer to Wiring Diagram Set 112, Passive Anti-Theft System for schematic and connector information Electrical Diagrams.

Normal Operation

The Passive Anti-Theft System (PATS) transceiver receives voltage from the Smart Junction Box (SJB) fuse 36 (5A). The PATS (Passive Anti-Theft System) transceiver and the Instrument Cluster (IC) communicate on the transmit (TX) and receive (RX) circuits. The IC (Instrument Cluster) compares the key code stored in memory and enables the engine to start if the key code is correct.

- DTC B1681 (PATS (Passive Anti-Theft System) Transceiver Module Signal Is Not Received)- sets when the PATS (Passive Anti-Theft System) transceiver signal is not received by the IC (Instrument Cluster). This DTC can be caused by circuits to the PATS (Passive Anti-Theft System) transceiver, circuits between the PATS (Passive Anti-Theft System) transceiver and the IC (Instrument Cluster), the PATS (Passive Anti-Theft System) transceiver or the IC (Instrument Cluster). This can also be caused by using the incorrect PATS (Passive Anti-Theft System) transceiver part number.

This pinpoint test is intended to diagnose the following:

- Fuse

- Wiring, terminals or connectors

- PATS (Passive Anti-Theft System) key

- PATS (Passive Anti-Theft System) transceiver

- IC (Instrument Cluster)

PINPOINT TEST G : DTC B1681

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) can damage the connector.

NOTE: Failure to disconnect the battery will result in false resistance readings.

G1 CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER POWER CIRCUIT FOR VOLTAGE

- Ignition OFF.

- Disconnect: PATS (Passive Anti-Theft System) Transceiver C252.

- Ignition ON.

- Measure the voltage between the PATS (Passive Anti-Theft System) transceiver C252-1, circuit CBP36 (BU/BN), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to G2.

No
VERIFY the SJB (Smart Junction Box) fuse 36 (5A) is OK. If OK, REPAIR the circuit. CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short Electrical Diagrams.

G2 CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER GROUND CIRCUIT FOR AN OPEN

- Ignition OFF.

- Disconnect: Negative Battery Cable.

- Measure the resistance between the PATS (Passive Anti-Theft System) transceiver C252-2, circuit GD112 (BK/GN), harness side and ground.





Is the resistance less than 5 ohms?

Yes
CONNECT the negative battery cable. GO to G3.

No
REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test. TEST the system for normal operation.

G3 CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER RECEIVE CIRCUIT FOR VOLTAGE

NOTICE: This pinpoint test step directs testing circuits using a back-probe method. Use the special back-probe tool specified in the tool list. Do not force test leads or other probes into connectors. Adequate care must be exercised to avoid connector terminal damage while ensuring that good electrical contact is made with the circuit or terminal. Failure to follow these instructions may cause damage to wiring, terminals, or connectors and subsequent electrical faults.

- Connect: PATS (Passive Anti-Theft System) Transceiver C252.

- Ignition ON.

- Measure the voltage by back-probing between the PATS (Passive Anti-Theft System) transceiver C252-4, circuit VRT23 (VT/GY), harness side and ground.





Is the voltage greater than 8 volts?

Yes
GO to G6.

No
GO to G4.

G4 CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER RECEIVE CIRCUIT FOR A SHORT TO GROUND

- Ignition OFF.

- Disconnect: IC (Instrument Cluster) C220.

- Disconnect: PATS (Passive Anti-Theft System) Transceiver C252.

- Measure the resistance between the PATS (Passive Anti-Theft System) transceiver C252-4, circuit VRT23 (VT/GY), harness side and ground.





Is the resistance greater than 10,000 ohms?

Yes
GO to G5.

No
REPAIR the circuit. CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test. TEST the system for normal operation.

If DTC B1681 is retrieved again, GO to G12.

G5 CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER RECEIVE CIRCUIT FOR AN OPEN

- Measure the resistance between the IC (Instrument Cluster) C220-3, circuit VRT23 (VT/GY), harness side and the PATS (Passive Anti-Theft System) transceiver C252-4, circuit VRT23 (VT/GY), harness side.





Is the resistance less than 5 ohms?

Yes
GO to G12.

No
REPAIR the circuit. CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test. TEST the system for normal operation.

G6 CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER TRANSMIT CIRCUIT FOR VOLTAGE

NOTICE: This pinpoint test step directs testing circuits using a back-probe method. Use the special back-probe tool specified in the tool list. Do not force test leads or other probes into connectors. Adequate care must be exercised to avoid connector terminal damage while ensuring that good electrical contact is made with the circuit or terminal. Failure to follow these instructions may cause damage to wiring, terminals, or connectors and subsequent electrical faults.

NOTE: Replacement of the PATS (Passive Anti-Theft System) transceiver does not require the PATS (Passive Anti-Theft System) keys to be programmed into the IC (Instrument Cluster) again.

- Measure the voltage by back-probing between the PATS (Passive Anti-Theft System) transceiver C252-3, circuit VRT24 (YE/OG), harness side and ground.





Is the voltage greater than 8 volts?

Yes
INSTALL a new PATS (Passive Anti-Theft System) transceiver. REFER to Passive Anti-Theft System (PATS) Transceiver . CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test. TEST the system for normal operation.

If DTC B1681 is retrieved again, GO to G12.

No
GO to G7.

G7 CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER TRANSMIT CIRCUIT FOR A SHORT TO GROUND WITH THE PATS (Passive Anti-Theft System)
TRANSCEIVER CONNECTED

- Ignition OFF.

- Disconnect: IC (Instrument Cluster) C220.

- Measure the resistance between the IC (Instrument Cluster) C220-4, circuit VRT24 (YE/OG), harness side and ground.





Is the resistance greater than 10,000 ohms?

Yes
GO to G9.

No
GO to G8.

G8 CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER TRANSMIT CIRCUIT FOR A SHORT TO GROUND WITH THE PATS (Passive Anti-Theft System) TRANSCEIVER DISCONNECTED

NOTE: Replacement of the PATS (Passive Anti-Theft System) transceiver does not require the PATS (Passive Anti-Theft System) keys to be programmed into the IC (Instrument Cluster) again.

- Disconnect: PATS (Passive Anti-Theft System) Transceiver C252.

- Measure the resistance between the IC (Instrument Cluster) C220-4, circuit VRT24 (YE/OG), harness side and ground.





Is the resistance greater than 10,000 ohms?

Yes
INSTALL a new PATS (Passive Anti-Theft System) transceiver. REFER to Passive Anti-Theft System (PATS) Transceiver . CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test. TEST the system for normal operation.

No
REPAIR the circuit. CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test. TEST the system for normal operation.

G9 CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER TRANSMIT CIRCUIT FOR AN OPEN

- Disconnect: PATS (Passive Anti-Theft System) Transceiver C252.

- Measure the resistance between the IC (Instrument Cluster) C220-4, circuit VRT24 (YE/OG), harness side and the PATS (Passive Anti-Theft System) transceiver C252-3, circuit VRT24 (YE/OG), harness side.





Is the resistance less than 5 ohms?

Yes
GO to G10.

No
REPAIR the circuit. CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test. TEST the system for normal operation.

G10 CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER TRANSMIT CIRCUIT FOR VOLTAGE

NOTICE: This pinpoint test step directs testing circuits using a back-probe method. Use the special back-probe tool specified in the tool list. Do not force test leads or other probes into connectors. Adequate care must be exercised to avoid connector terminal damage while ensuring that good electrical contact is made with the circuit or terminal. Failure to follow these instructions may cause damage to wiring, terminals, or connectors and subsequent electrical faults.

NOTE: Replacement of the PATS (Passive Anti-Theft System) transceiver does not require the PATS (Passive Anti-Theft System) keys to be programmed into the IC (Instrument Cluster) again.

- Connect: PATS (Passive Anti-Theft System) Transceiver C252.

- Connect: IC (Instrument Cluster) C220.

- Connect the scan tool.

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: IC (Instrument Cluster) DataLogger.

- Trigger the IC (Instrument Cluster) active command TRANSMIT SIGNAL to on.

- NOTE: The voltage only reads for a very short period of time. Make sure to monitor the meter closely while triggering the active command on.
Measure the voltage by back-probing between the PATS (Passive Anti-Theft System) transceiver C252-3, circuit VRT24 (YE/OG), harness side and ground.






Is the voltage less than 5 volts?

Yes
INSTALL a new PATS (Passive Anti-Theft System) transceiver. REFER to Passive Anti-Theft System (PATS) Transceiver . CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test. TEST the system for normal operation.

No
GO to G11.

G11 CHECK THE PATS (Passive Anti-Theft System) TRANSCEIVER TRANSMIT CIRCUIT FOR A SHORT TO VOLTAGE

- Ignition OFF.

- Disconnect: IC (Instrument Cluster) C220.

- Disconnect: PATS (Passive Anti-Theft System) Transceiver C252.

- Ignition ON.

- Measure the voltage between the PATS (Passive Anti-Theft System) transceiver C252-3, circuit VRT24 (YE/OG), harness side and ground.





Is any voltage indicated?

Yes
REPAIR the circuit. CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test. TEST the system for normal operation.

No
GO to G12.

G12 CHECK FOR CORRECT IC (Instrument Cluster) OPERATION

NOTE: When using the Integrated Diagnostic System (IDS), the IC (Instrument Cluster) and the Transmission Control Module (TCM) parameters are reset at the same time.

- Disconnect the IC (Instrument Cluster) connector.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect the IC (Instrument Cluster) connector and make sure it seats correctly.

- Operate the system and verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new IC (Instrument Cluster). CARRY OUT the parameter reset procedure on both modules. REFER to Passive Anti-Theft System (PATS) Parameter Reset . PROGRAM the PATS (Passive Anti-Theft System) keys into the IC (Instrument Cluster). REFER to Integrated Keyhead Transmitter (IKT) Key Programming Using Diagnostic Equipment . CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

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